Releasable plow



June 2, 1931. o. A. K. PRINTZ 1,303,477

RELEASABLE PLOW Filed Sept. 11, 1950 iiled February 2, 1929.

Patented June 2, 1931 UNITED STATES OSCAR ADOLF KRISTIAN' PRINTZ, OF OVEBUM,.-SWEDEN RELEASABLE PLow Application filed September 11, 1930, Serial No. 481,298, and in Sweden April 22, 1930.

This invention relates to releasable plows and more particularly to an improvement in the releasable plow which is set forth in my copending application Serial No. 342,830,

In the specification of said application a spring controlled device is described and claimed which has for its object to allow the plow base to swing back when encountering an obstacle in the ground which overcomes the action of the spring in order thereby to avoid damage of the plow. According to said application the plowbase which is pivotally connected to the plow frame, is held in working position by a spring controlled two-armed pivoted lever which is mounted freely both with respect to the spring and to the plow base or body, so that it has only frictional engagement therewith, the lever arm cooperating with the spring being so shaped as torelieve the plow base from the action of the spring already after a very slight compression of the spring due to a correspondingly slight turning of said lever out of its normal or locking position so that the spring will allow the necessary continued turning of the lever to effect the release of the plow beam without afiording any increased resistance thereto. This will permit the use of a very powerful springcapable of securing a steady motlon of the plow base irrespective of varying resistance in the ground.

the device above referred tothat arm of the two-armed lever which cooperates withsay, with the spring compressed and the plow base swung back out ofengagement with the lever, a serious wedge-actlon w1ll be produced between said camsurface and said roller and the upper portion of said bearing as result of the relative position of said parts. The

stress on said parts as well as the friction therebetween will be very large due to the powerful spring used, and may result in breakage of said parts or in such a wear or deformation of the cam surface that the device cannot act in the manner desired, espe cially, that the plow basecannot be brought back to working position against the action of the spring by a backward drive ofthe plow.

The object of this invention is to overcome said drawbacks. The invention is characterized, chiefly, by the provision of a movable stop member controlled by said two-armed lever and adapted to beheld out of engagement with the spring, as long as the lever holds the plow base in working position, but

will be brought to a position in which it will take up thespring pressure and prevent the same from acting onthe lever, as soon as the lever is moved to release the plow base.

In the accompanying drawings one em bodiment of the invention is shown. Fig. 1 is aside elevation of the plow base in working position, and F ig. Qis a side elevation of the plow base, after it has been released and swungback. V

The plow beam 2 with; the plow base 3"is .mounted in the plow frame lby a pivotfil.

which connects the bearing'member '5 attached to the plow beam 2 with the bracket 6 attached to the plow frame 1. The free end of the beam 2 is normallyin engagement. with the frame. 1 and bears against the lower surface of a stop shoulder 21 situated at the upper edge of the frame and adjustable in vertical direction of a screw or the like. I

Pivotally mounted at 15 in the frame in front of the free end of theib'eam2- is. a bell crank lever 16. The lower end of the lever 16 is shaped as a fork carrying a roller 17 by means of the pivot 18. The upper end of the lever 16 is shaped as a cam 19 the foremost portion of which is concentric or substantially concentric with respect to the pivot 15. At its side facing the bracket 14 the upper armof the lever 16 is formed with a projection 20.

Attached to the frame 1 on the opposite side of the lever 16 with respect to the bracket 14 is a bracket 21. Mounted on a pivot 22 in the bracket 21 is a fork-shaped lever 23.

A roller 24 mounted on a pivot in the lever 23.

between the arms thereof engages an elongated slot 25 formed in thelever 16. The

construction of the device, as faras its further details is concerned, will best appear from a description of its operation.

In the working position of the plow base, as shown in Fig. 1, the roller 13 of the fork 11 is held by the action of the sprin 10 against the rear straight edge of the upper arm of lever 16. The pressure thus resulting will be transmitted through the roller 17 to the lower edge of the front end of the beam 2 which is thus pressed upwards against the fixed stop shoulder 21 thereby maintaining the beam with its plow base in working position. Should there be any hindrance to the forward motion of the plow base sufficiently great to overcome the tension of spring 10 the plow base will turn rearwardly around the pivot 4 in the direction of the arrow.

In this turning movement the front end of the beam 2 is depressed causing the lever 16 to turn to the position shown in Fig. 2, whereas the fork 11 which is movable parallel to the frame 1 will be pressed rearwardly by the'upper arm of the lever 16 while compressin the spring 10 until that portion of the 'sur .ace 19 which is concentric with respect to the pivot 15 comes into contact with the roller 13. In this turning movement of the lever 16 the fork-shaped lever 23 will be moved downwardly due to the engagement between. its roller 24 and the slot 25 in lever 16. At the time by whichthe roller 13 is} about to slide up on the concentric portion of cam surface 19 the roller 24 has been moved by the slot 25 to a position in which the free end of the lever 23 has come into contactwith the roller 13, and during the continued turning movement of the lever 16 in order to allow the free end of the beam 2 to pass beyond the roller 17 the action of the spring 10 will, consequently, be transmitted to the fork-shaped lever 23. The point of contact between the fork-shaped lever 23 and the spring controlled roller 13is situated on the line of direction of the spring action which line also passes through the centre of movement 22 of the fork-shaped lever 23.

In this way the wedge-action above referred to will be eliminated. and, moreover, the

stress on the various parts as well as the fric- 31011 therebetween will be considerably reuced.

In order to enable a compression of the spring 10 by hand for the purpose of disman-- 1. In a plow the combination with the plow frame of a plow beam pivotally connected thereto, a'plow base carried by said beam, a lever pivotally mounted in the plow frame to be engaged by the free end of the plow beam to hold the plow base in working position, a

spring arranged to act on said lever without being mechanically connected thereto to maintain said engagement and to be compressed to allow the lever to release the plow beam, when the plow base is forced out of working position due to a resistance in the ground, and a stop memberto relieve the lever from the action of the spring when com-.

pressed and maintain the spring in compressed state. 7

2. In a plow the combination with the plow frame of a plow beam pivotally connected thereto, a plow base carried by said beam, a lever pivotallymounted in the plow frame to be engaged by the freeend of saidbeam to hold the plow base in' working position when in normal position, a spring arranged to act on said lever without being mechanically connected thereto to maintain said engagement, said lever being so shaped as to be capable of releasing theplow beam after a slight compression oftbe spring due to a slight turning of the lever from its normal position, and a.

stop member arranged to'be. out of engagement with the spring when the lever is in normal position, and to be brought to a position in which it relieves the lever from theaction of the springand maintains the spring in compressed state after the lever has been swung from its normal position sufliciently to release the plow beam.

3. In a plow the combination with the plow frame of a plow beam pivotally connected thereto, a plow base carried by said beam, a

lever pivotally mounted in the plow frame to be engaged by the free end of said beam to hold the plow base in working position when in normal position, a'spring arranged to act on said lever withoutbeing mechanically con- Y nected thereto to maintain said engagement, said lever being so shaped astocompress the able re spring during a first turning from its normal position and be capable of continued turning independently of the spring to enable releasing of the plow beam, and a stop member controlled by said lever in such a way as to be outof engagement with the spring in the normal position of said lever and be brought to a position in which it maintains the spring in compressed state after the lever has been turned to compress the spring.

4. In a plow the combination with the plow frame .of a plow beam pivotally connected thereto, a plow base carried by said beam, a lever pivotally mounted in the plow frame to be engaged by the free end of said beam to hold the plow base in working position when in normal position, a spring arranged to act on said lever without being mechanically connected thereto to maintain said engagement, said lever being so shaped as to compress the spring during a first turning from its normal position and be capable of continued turning independently of the spring to eneasing of the plow beam, another lever pivotally connected to a bracket on the plow frame, and a connection between said firstmentioned lever and said other lever so arranged as to hold said other lever out of engagement with the spring in the normal position of said firstmentioned lever and bring it to a position in which it maintains the spring in compressed state after the firstmentioned lever has been turned to compress the spring.

5. In a plow the combination with the plow frame of a plow beam pivotally connected thereto, a plow base carried by said beam, a lever pivotally mounted in the plow frame to be engaged by the free end of said beam to hold the plow base in working position when in normal position, a spring arranged to act on said lever without being mechanically connected thereto to maintain said engagement, said lever being so shaped as to compress the spring during a first turning from its normal position and be capable of continued turning independently of the spring to enable releasing of the plow beam, another lever pivotally connected to a bracket on a point of the plow frame situated on or substantially on the line of direction of the action of said spring, and a connection between said firstmentioned lever and said other lever so arranged as to hold said other lever out of engagement with the spring in the normal position of said firstmentioned lever and bring it to a position in which itmaintains the spring in compressed state after the firstmentioned lever has been turned to compress the spring.

6. In a plow the combination with a plow frame of a plow beam pivotally connected thereto, a plow base carried by said beam, a two-armed lever pivotally mounted in the plow frame, one arm of said lever being adapted to be engaged by the free end of the plow beam to hold the plow base in working position when in normal position, a spring to act on the other arm of said lever without being mechanically connected thereto to maintain said engagement, said other arm of the lever being so shaped as to compress the spring during a first turning of the lever from its normal position and be capable of continued turning independently of the spring so as to be allowed to release the plow beam after said slight compression of the spring, another lever pivotally connected to a bracket on the plow frame, a connection between said other lever and said firstmentioned lever so arranged as to hold the other lever out of engagement with the spring in the normal position of the firstmentione-d lever and bring it to a position to serve as a stop for said spring to relieve the firstmentioned lever from the action of the spring after said lever has been moved to compress the spring, and means on said firstmentioned lever operated by the plow beam automatically to restore the engagement between the plow beam and said lever by a backward drive of the plow.

7. In a plow the combination with the plow frame of a plow beam pivotally connected thereto, a plow base carried by said beam, a two-armed lever pivotally mounted in the plow frame, one arm of said lever be ing adapted to be engaged'by the free end of the plow beam to hold the plow base in working position when in normal position, a spring, a rigid guide member connected to the plow frame, a slidable member mounted in said guide member and connected to the spring to engage the other arm of said lever under the action of the spring, said other arm being so shaped as to compress the spring during a first turning of the lever from its normal position and be capable of continued turning independently of the spring so as to be allowed to release the plow beam after said slight compression of the spring, another lever pivotally connected to a bracket on the plow frame, a connection between said other lever and said firstmentioned lever so arranged as to hold the other lever out of engagement with said slidable member in the normal position of the firstmentioned lever and bring the other lever to a position to serve as a stop for said slidable member to relieve the first-mentioned lever from the action of the spring after it has been moved from its normal position to compress the spring, and means on said firstmentioned lever operated by the plow beam automatically to restore the engagement between the plow beam and the firstmentioned lever by a backward drive of the plow.

In testimony whereof I have signed my name.

4 OSCAR ADOLF KRISTIAN PRINTZ. 

